There are approximately 4 million deliveries per year in the US and childbirth is the second leading cause of hospitalization. Thus, quality assessment in obstetrics may provide critical insights into improving the medical care system. This study seeks to understand the elements of hospital structure and of obstetrical processes of care that influence intrapartum quality of care. The two primary hypotheses are: 1) The hospital structural factor that is most likely to be significant is the level of perinatal care provided; 2) The process of care factor that is most likely to be significant is induction of term labor. We propose the following specific aims: 1) Build primary cesarean delivery risk adjustment models and classify hospitals by quality as measured by their expected and actual primary cesarean delivery rates; 2) Determine the association between hospital quality and hospital structural and process of care factors; 3) Develop and validate models of the relationships between hospital structural and process of care factors and risk-adjusted primary cesarean rates. [unreadable] [unreadable] Risk-adjusted cesarean rates will be used as a quality indicator. California linked birth certificate and maternal and neonatal hospital discharge data will be used to risk adjust primary cesarean delivery rates. Hospitals that are significantly above or below expected primary cesarean delivery rates will be considered quality outliers. Hospital structure information will be obtained from the American Hospital Association Hospital survey. We will assess the association of various hospital structures and patient care processes with hospital quality. Our analytic tasks begin with careful risk-adjustment of primary cesarean delivery rates, including detailed logistic regression model fit assessment, assumption checking, and bootstrap validation. Next, we will classify all California obstetric hospitals as poor quality or good quality on the basis of their adjusted rates of primary cesarean deliveries and then compare poor to good quality hospitals on a variety of structural and process measures. Finally, we will build a model of the relationships between several elements of hospital structure and processes of care and risk-adjusted primary cesarean rates. Understanding the influences on intrapartum quality of care is necessary before planning future quality improvement strategies. [unreadable] [unreadable]